Recently, disk-shaped recording media, such as the optical disks or magneto-optical disks employing the optical or magneto-optical signal recording/reproducing method, have been evolved, and are being offered to the market. As these disk-shaped recording media, there are known the recording media of the read only memory (ROM) type, such as the so-called compact disk (CD), the recording media of the so-called write once type in which data writing is feasible only once by the user, and the recording media in which the data rewriting (so-called overwriting) is possible, such as the magneto-optical disk. As one of the techniques for realizing a unified recording format for these various recording media, there is proposed a so-called sampled servo technique in which, similarly to the so-called sector servo in a hard disk in the field of the magnetic disk, servo signals are recorded previously on the spiral or concentric tracks at predetermined intervals or angles (so-called preformating), these discrete signals being sampled and held at the time of the rotative driving of the disk to effect continuous servo control. As this kind of the disk-shaped recording medium, there is known to data an optical disk d shown for example in FIG. 9. Wherein clock information pits arranged on a track center line, a pair of tracking information pits spaced by a predetermined distance from said clock information pits and positioned on the inner and outer sides of said track center line and pairs of traverse information pits spaced by a distance allocated to each of said recording tracks and arranged on said track center line, are provided tracks tk, is mounted on a recording/reproducing device and rotated in the direction of an arrow mark r for information recording or reproduction employing the optical beam.
Each of the sectors SC.sub.1, SC.sub.2, . . . SC.sub.m in each circular track is provided at towards its incipient side with an address information section ad followed by a predetermined number n of blocks bl.sub.1, bl.sub.2, . . . , bl.sub.n, (where n=43, as an example). As far as the blocks bl.sub.1, bl.sub.2, . . . , bl.sub.n are concerned a plurality of registering blocks among the sectors, such as the block bl.sub.1 among the sectors SC.sub.1, SC.sub.2, . . . SC.sub.m, are aligned in the radial direction of this optical disk d. Each of the blocks bl.sub.1, bl.sub.2, . . . , bl.sub.n of each of the sectors SC.sub.1, SC.sub.2, . . . , SC.sub.m is provided towards its incipient end with a control recording area ar.sub.C, following by an information writing area ar.sub.D to constitute a unit information division. In the control recording area ar.sub.C of each of the blocks bl.sub.1, bl.sub.2, . . . , bl.sub.n, tracking information pits q.sub.a and q.sub.b, positioned on the outer and inner sides of a track center line k.sub.c, and a clock information pit q.sub.c, positioned on the track center line k.sub.c, are formed in advance along the center line k.sub.c with a predetermined distance from one another. Referring to the array on the disk of the information pits q.sub.a, q.sub.b and the clock information pits q.sub.c in a direction orthogonal to the track centerline k.sub.c, that is, the radial direction of the optical disk d, the track information pits q.sub.b and the clock information pits q.sub.c are arrayed radially each on a straight line, whereas the track information pits q.sub.a are arrayed so that these pits are shifted in the longitudinal direction of the track t.sub.k at intervals of, for example, 16 consecutive tracks. When the optical disk d, provided in each control recording area ar.sub.c thereof with the tracking information pits q.sub.a and q.sub.b and the clock information pit q.sub.c, is mounted on the recording/reproducing apparatus for information recording or reproduction by an optical beam, the tracking information pits q.sub.a, q.sub.b and the clock information pit q.sub.c of the control recording area ar.sub.C are read by the optical beam, with the tracking information pit q.sub.a being sampled by a sampling pulse SP.sub.1 or SP.sub.2, the tracking information pit q.sub.a being sampled by a sampling pulse SP.sub.3, the clock information pit q.sub.c being sampled by the sampling pulse SP.sub.5 and the mirror surface area between the tracking information pit q.sub.b and the clock information pit q.sub.c being sampled by the sampling pulse SP.sub.4 so as to be utilized for servicing in various ways or for clock generation. Thus the clocks are regenerated from reproducing outputs of the clock information pits q.sub.c to generate the necessary timing clock while the tracking error is found on the basis of the reproducing output of the tracking information pits q.sub.a and q.sub.b positioned on the outer and inner sides of the track center line k.sub.c to effect tracking control or to effect focusing control on the basis of the reproducing output of the mirror surface region. The reproducing outputs of the tracking information pits q.sub.a, arranged with a shift at intervals of 16 consecutive tracks, as described hereinabove, are utilized to perform a so-called traverse count to find the number of the tracks being scanned by the optical pickup.
It will be noted that the tracking information pits q.sub.a, q.sub.b and the clock information pits q.sub.c, preformated on the optical disk d as described hereinabove, are formed as physical projections and recesses which, in the actual optical disk, are thermally transferred to a disk base plate by a stamper.
When injection molding the disk substrate, on which the tracking information pits q.sub.a and q.sub.b and the clock information pits q.sub.c, preformated on the optical disk d as described above, are previously thermally transferred by the above stamper, it may occur that so-called ghost pits are locally generated, such as by thermal shrinkage of the disk substrate, along the radial direction of the disk. Hence, in the conventional optical disk d in which the tracking information pits q.sub.a are shifted at intervals of 16 consecutive tracks, so as to be useful in the traverse counting, there is the risk that the reproducing output of the track information pits q.sub.a is affected by the ghost pits and cannot be used for proper detection of the tracking error resulting in unstable clock reproduction due to mistracking. Also, in the above described optical disk d, the array of the tracking information pits q.sub.a in which the tracking information pits q.sub.a are shifted in their positions at intervals of 16 consecutive tracks so as to be useful in traverse counting, it is only possible to perform traverse counting at intervals of 16 tracks, that is, R rough traverse counting, while it is not possible to perform a more precise traverse counting at intervals of one track.
In view of the above described convenience of the prior art system, the present invention provides a disk-shaped recording medium in which recording tracks forming a large number of circular turns are formed on an annular recording surface section for surrounding a central hole formed in said annular recording surface section, each of said turns of said recording tracks including a predetermined number of recording regions, corresponding ones of said recording regions among said turns of said recording tracks being arrayed in the radial direction of the recording surface section, each of said recording sections including a control recording region and an information writing region consecutive thereto, and a disk apparatus employing the above disk-shaped recording medium, wherein clocks may be reproduced reliably under stable tracking control and traverse counting of the recording tracks may be performed with high accuracy on the track-by-track basis.